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Mendel Friedman - One of the best experts on this subject based on the ideXlab platform.
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Glycoalkaloid content of some superior potato solanum tuberosum l clones and commercial cultivars
Archives of Phytopathology and Plant Protection, 2009Co-Authors: G K Kirui, Mendel Friedman, A K Misra, O M Olanya, R Elbedewy, P T EwellAbstract:Abstract Glycoalkaloids are important metabolites in potato because of their toxic properties and potential harmful effects to humans. To validate a rapid assay to determine and quantify Glycoalkaloid content and its distribution in potato tubers, we have characterized and quantified, by HPLC and by colorimetry with bromphenol blue, the Glycoalkaloids in 15 potato cultivars and experimental clones grown in the tropical climate of Kenya. There was significant correlation of TGA by HPLC and colorimetry. Significant differences in Glycoalkaloid content were detected among potato cultivars. The concentration of α-chaconine in the 15 cultivars ranged from 1.62 to 4.46 mg/100 g fresh weight (fwt), of α-solanine from 1.45 to 4.51 mg/100 g, and of solanidine from 1.58 to 5.21 mg/100 g. Total Glycoalkaloid values (TGA, sum of the three compounds) for the 15 cultivars determined by HPLC ranged from 5.31 to 15.39 mg/100 g and the corresponding values determined by bromphenol blue colorimetry, from 3.51 to 17.48 mg/1...
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Potato Glycoalkaloids and metabolites : Roles in the plant and in the diet
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Mendel FriedmanAbstract:Potatoes, members of the Solanaceae plant family, serve as major, inexpensive low-fat food sources providing energy (starch), high-quality protein, fiber, and vitamins. Potatoes also produce biologically active secondary metabolites, which may have both adverse and beneficial effects in the diet. These include Glycoalkaloids, calystegine alkaloids, protease inhibitors, lectins, phenolic compounds, and chlorophyll. Because Glycoalkaloids are reported to be involved in host-plant resistance and to have a variety of adverse as well as beneficial effects in cells, animals, and humans, a need exists to develop a clearer understanding of their roles both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the (a) history of Glycoalkaloids; (b) Glycoalkaloid content in different parts of the potato plant, in processed potato products, and in wild, transgenic, and organic potatoes; (c) biosynthesis, inheritance, plant molecular biology, and Glycoalkaloid−plant phyto...
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Potato Glycoalkaloids and metabolites: Roles in the plant and in the diet
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Mendel FriedmanAbstract:Potatoes, members of the Solanaceae plant family, serve as major, inexpensive low-fat food sources providing energy (starch), high-quality protein, fiber, and vitamins. Potatoes also produce biologically active secondary metabolites, which may have both adverse and beneficial effects in the diet. These include Glycoalkaloids, calystegine alkaloids, protease inhibitors, lectins, phenolic compounds, and chlorophyll. Because Glycoalkaloids are reported to be involved in host-plant resistance and to have a variety of adverse as well as beneficial effects in cells, animals, and humans, a need exists to develop a clearer understanding of their roles both in the plant and in the diet. To contribute to this effort, this integrated review presents data on the (a) history of Glycoalkaloids; (b) Glycoalkaloid content in different parts of the potato plant, in processed potato products, and in wild, transgenic, and organic potatoes; (c) biosynthesis, inheritance, plant molecular biology, and Glycoalkaloid-plant phytopathogen relationships; (d) dietary significance with special focus on the chemistry, analysis, and nutritional quality of low-Glycoalkaloid potato protein; (e) pharmacology and toxicology of the potato Glycoalkaloids comprising alpha-chaconine and alpha-solanine and their hydrolysis products (metabolites); (f) anticarcinogenic and other beneficial effects; and (g) possible dietary consequences of concurrent consumption of Glycoalkaloids and other biologically active compounds present in fresh and processed potatoes. An enhanced understanding of the multiple and overlapping aspects of Glycoalkaloids in the plant and in the diet will benefit producers and consumers of potatoes.
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the folic acid analogue methotrexate protects frog embryo cell membranes against damage by the potato Glycoalkaloid α chaconine
Food and Chemical Toxicology, 2000Co-Authors: M L Mcwilliams, James T Blankemeyer, Mendel FriedmanAbstract:Abstract As part of an effort to improve the safety of plant foods, a need exists to more clearly delineate the mechanisms of toxicities of Glycoalkaloids, which may be present in Solanum plant species such as potatoes, tomatoes and eggplants. α-Chaconine is a major Glycoalkaloid present in potatoes. To assess the possible influence of structure of pteridine derivatives on toxicity of potato Glycoalkaloids, a previous study that demonstrated the protective effects of folic acid against the Solanum Glycoalkaloid α-chaconine-induced toxicity on Xenopus laevis frog embryo cell membranes was extended to two folate analogues—a synthetic compound widely used as a therapeutic agent methotrexate, and naturally occurring l -monapterin. Adverse effects on embryos were evaluated by observing changes in membrane potentials with an electrochromic dye, di-4-ANEPPS, as a fluorescent probe for the integrity of the membranes. Methotrexate decreased α-chaconine-induced polarization, as did folic acid. This decrease may result from an alteration of membrane conformations that prevents the binding of the Glycoalkaloid to the membrane receptor sites, and/or from effects on folic acid metabolism. In contrast, l -monapterin did not significantly reduce the α-chaconine-induced toxicity. The possible significance of these results to food safety is discussed.
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lowering of plasma ldl cholesterol in hamsters by the tomato Glycoalkaloid tomatine
Food and Chemical Toxicology, 2000Co-Authors: Mendel Friedman, T E Fitch, W E YokoyamaAbstract:Abstract Tomatoes contain the steroidal Glycoalkaloid tomatine, which has been reported to form strong, insoluble complexes with cholesterol in vitro . To determine whether tomatine can reduce dietary cholesterol absorption and plasma levels of cholesterol and triglycerides, we fed hamsters a high-fat, high-cholesterol diet with 0.05–0.2% added tomatine in the diet. The tomatine diets induced lowering of serum low-density lipoprotein (LDL) without changing high-density lipoprotein (HDL) cholesterol. Compared to the control diets, four- to fivefold more labeled dietary cholesterol and coprostanol was excreted in the feces of the tomatine-fed hamsters. The amount of cholesterol excreted in the feces corresponded to the amount of tomatine in the diet. These observations suggest that due to the formation of an insoluble tomatine–cholesterol complex and its excretion in the feces, very little dietary tomatine is absorbed from the digestive tract into the blood stream. They are also consistent with the reported low oral toxicity of tomatine compared to other Glycoalkaloids.
James T Blankemeyer - One of the best experts on this subject based on the ideXlab platform.
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the folic acid analogue methotrexate protects frog embryo cell membranes against damage by the potato Glycoalkaloid α chaconine
Food and Chemical Toxicology, 2000Co-Authors: M L Mcwilliams, James T Blankemeyer, Mendel FriedmanAbstract:Abstract As part of an effort to improve the safety of plant foods, a need exists to more clearly delineate the mechanisms of toxicities of Glycoalkaloids, which may be present in Solanum plant species such as potatoes, tomatoes and eggplants. α-Chaconine is a major Glycoalkaloid present in potatoes. To assess the possible influence of structure of pteridine derivatives on toxicity of potato Glycoalkaloids, a previous study that demonstrated the protective effects of folic acid against the Solanum Glycoalkaloid α-chaconine-induced toxicity on Xenopus laevis frog embryo cell membranes was extended to two folate analogues—a synthetic compound widely used as a therapeutic agent methotrexate, and naturally occurring l -monapterin. Adverse effects on embryos were evaluated by observing changes in membrane potentials with an electrochromic dye, di-4-ANEPPS, as a fluorescent probe for the integrity of the membranes. Methotrexate decreased α-chaconine-induced polarization, as did folic acid. This decrease may result from an alteration of membrane conformations that prevents the binding of the Glycoalkaloid to the membrane receptor sites, and/or from effects on folic acid metabolism. In contrast, l -monapterin did not significantly reduce the α-chaconine-induced toxicity. The possible significance of these results to food safety is discussed.
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folic acid protects against potato Glycoalkaloid α chaconine induced disruption of frog embryo cell membranes and developmental toxicity
Journal of Agricultural and Food Chemistry, 1997Co-Authors: Mendel Friedman, Craig F Burns, Cathy A Butchko, James T BlankemeyerAbstract:To demonstrate whether folic acid can protect Xenopus embryos against reported adverse effects of the potato Glycoalkaloid α-chaconine, the frog embryos were exposed simultaneously to the Glycoalkaloid, folic acid (pteroylglutamic acid), and an electrochromic fluorescent dye, Di-4-ANEPPS, in a specially designed instrument that measures embryonic membrane potential. Folic acid decreased the chaconine-induced fluorescence, with a maximum decrease occurring at about 10 mg/L of both folic acid and the Glycoalkaloid dissolved in solution. The protective effect was also operative in the frog embryo teratogenesis assayXenopus (FETAX), in which survival and teratogenicity of the whole embryos were the endpoints. Possible mechanisms of the protective effect and the possible significance of the results to food safety and health are discussed. Keywords: α-Chaconine; folic acid; food safety; frog embryos; Glycoalkaloids; membrane potential; potatoes; teratogenicity
Jørgen Christiansen - One of the best experts on this subject based on the ideXlab platform.
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A major QTL and an SSR marker associated with Glycoalkaloid content in potato tubers from Solanum tuberosum × S. sparsipilum located on chromosome I
Theoretical and Applied Genetics, 2008Co-Authors: Kirsten Kørup Sørensen, Kerstin Olsson, Hanne Grethe Kirk, Rodrigo Labouriau, Jørgen ChristiansenAbstract:New potato ( Solanum tuberosum ) varieties are required to contain low levels of the toxic Glycoalkaloids and a potential approach to obtain this is through marker-assisted selection (MAS). Before applying MAS it is necessary to map quantitative trait loci (QTLs) for Glycoalkaloid content in potato tubers and identify markers that link tightly to this trait. In this study, tubers of a dihaploid BC_1 population, originating from a cross between 90-HAF-01 ( S. tuberosum _1) and 90-HAG-15 ( S. tuberosum _2 × S. sparsipilum ), were evaluated for content of α-solanine and α-chaconine (total Glycoalkaloid, TGA) after field trials. In addition, tubers were assayed for TGA content after exposure to light. A detailed analysis of segregation patterns indicated that a major QTL is responsible for the TGA content in tubers of this potato population. One highly significant QTL was mapped to chromosome I of the HAG and the HAF parent. Quantitative trait loci for Glycoalkaloid production in foliage of different Solanum species have previously been mapped to this chromosome. In the present research, QTLs for α-solanine and α-chaconine content were mapped to the same location as for TGA content. Similar results were observed for tubers exposed to light. The simple sequence repeat marker STM5136 was closely linked to the identified QTL.
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a major qtl and an ssr marker associated with Glycoalkaloid content in potato tubers from solanum tuberosum s sparsipilum located on chromosome i
Theoretical and Applied Genetics, 2008Co-Authors: Kirsten Kørup Sørensen, Hanne Grethe Kirk, Rodrigo Labouriau, K Olsson, Jørgen ChristiansenAbstract:New potato (Solanum tuberosum) varieties are required to contain low levels of the toxic Glycoalkaloids and a potential approach to obtain this is through marker-assisted selection (MAS). Before applying MAS it is necessary to map quantitative trait loci (QTLs) for Glycoalkaloid content in potato tubers and identify markers that link tightly to this trait. In this study, tubers of a dihaploid BC1 population, originating from a cross between 90-HAF-01 (S. tuberosum1) and 90-HAG-15 (S. tuberosum2 × S. sparsipilum), were evaluated for content of α-solanine and α-chaconine (total Glycoalkaloid, TGA) after field trials. In addition, tubers were assayed for TGA content after exposure to light. A detailed analysis of segregation patterns indicated that a major QTL is responsible for the TGA content in tubers of this potato population. One highly significant QTL was mapped to chromosome I of the HAG and the HAF parent. Quantitative trait loci for Glycoalkaloid production in foliage of different Solanum species have previously been mapped to this chromosome. In the present research, QTLs for α-solanine and α-chaconine content were mapped to the same location as for TGA content. Similar results were observed for tubers exposed to light. The simple sequence repeat marker STM5136 was closely linked to the identified QTL.
Mihajlo Z Stankovic - One of the best experts on this subject based on the ideXlab platform.
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liquid liquid systems for acid hydrolysis of Glycoalkaloids from solanum tuberosuml tuber sprouts and solanidine extraction
Medical Science Monitor, 2005Co-Authors: Nada C Nikolic, Mihajlo Z Stankovic, Dejan Z MarkovicAbstract:Background: Potato sprouts (Solanum tuberosum L.) contain steroidal Glycoalkaloids containing solanidine, an important precursor for hormone synthesis. Glycoalkaloids are reported to inactivate the Herpes simplex, Herpes zoster and Herpes genitalis viruses in humans, while Aglyones, including solasodine, may protect against skin cancer. Extracts of Glycoalkaloids or solanidine can be used to obtain a potential skin cancer preparation for clinical research. Material/Methods: Dried potato sprouts were used to obtain Glycoalkaloids and solanidine. The hydrolysis of Glycoalkaloids in a liquid-liquid system was performed using a reflux condenser, obtaining extracts of glycolakaloids from dried and milled potato tuber sprouts. Hydrochloric acid was then added to the extract to form the first (aqueous) phase, and chloroform, trichloroethylene or carbon tetrachloride to form the second (organic) phase of the liquid-liquid system. In this way, Glycoalkaloid hydrolysis to solanidine and solanidine extraction in the organic liquid phase were combined into a single step. IR and GC/MS analysis of solanidine was also conducted. Results: Based on the results we obtained, the optimal liquid-liquid system was found to be 2% w/v hydrochloric acid in a 50% (volume) methanolic extract of Glycoalkaloids from tuber sprouts, as the first phase, and chloroform as the second phase. Using this system, a yield of 1.46 g solanidine per 100 g of dried potato sprouts can be achieved. Conclusions: Glycoalkaloid hydrolysis in a liquid-liquid system yields the aglycone solanidine can be obtained from dried potato sprouts. The yield of solanidine is higher than that obtained using solid-liquid-liquid systems for Glycoalkaloid hydrolysis from potato vines.
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solanidine hydrolytic extraction and separation from the potato solanum tuberosum l vines by using solid liquid liquid systems
Journal of Agricultural and Food Chemistry, 2003Co-Authors: Nada C Nikolic, Mihajlo Z StankovicAbstract:Solanidine is a steroidal aglycon of potato (Solanum tuberosum L.) Glycoalkaloids and a very important precursor for the synthesis of hormones and some pharmacologically active compounds. Glycoalkaloids are hydrolyzed by mineral acid, yielding solanidine. This paper deals with the kinetics of solanidine hydrolytic extraction in different solid−liquid−liquid systems. The dried and milled potato (S. tuberosum L.) vines were used as a source of Glycoalkaloids and as the solid phase. The solutions of hydrochloric acid in 2 and 10% (w/v) aqueous acetic acid, in 50% (volume) aqueous methanol, and in 50% (volume) aqueous ethanol were first liquid phase, and the medium for Glycoalkaloid extraction from potato vines and their hydrolysis to solanidine. The chloroform, trichloroethylene, or carbon tetrachloride were the second, organic, liquid phase and the medium for solanidine extraction. This procedure combines three different processes: extraction of Glycoalkaloids from potato vines, their hydrolysis to solanid...
Kirsten Kørup Sørensen - One of the best experts on this subject based on the ideXlab platform.
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A major QTL and an SSR marker associated with Glycoalkaloid content in potato tubers from Solanum tuberosum × S. sparsipilum located on chromosome I
Theoretical and Applied Genetics, 2008Co-Authors: Kirsten Kørup Sørensen, Kerstin Olsson, Hanne Grethe Kirk, Rodrigo Labouriau, Jørgen ChristiansenAbstract:New potato ( Solanum tuberosum ) varieties are required to contain low levels of the toxic Glycoalkaloids and a potential approach to obtain this is through marker-assisted selection (MAS). Before applying MAS it is necessary to map quantitative trait loci (QTLs) for Glycoalkaloid content in potato tubers and identify markers that link tightly to this trait. In this study, tubers of a dihaploid BC_1 population, originating from a cross between 90-HAF-01 ( S. tuberosum _1) and 90-HAG-15 ( S. tuberosum _2 × S. sparsipilum ), were evaluated for content of α-solanine and α-chaconine (total Glycoalkaloid, TGA) after field trials. In addition, tubers were assayed for TGA content after exposure to light. A detailed analysis of segregation patterns indicated that a major QTL is responsible for the TGA content in tubers of this potato population. One highly significant QTL was mapped to chromosome I of the HAG and the HAF parent. Quantitative trait loci for Glycoalkaloid production in foliage of different Solanum species have previously been mapped to this chromosome. In the present research, QTLs for α-solanine and α-chaconine content were mapped to the same location as for TGA content. Similar results were observed for tubers exposed to light. The simple sequence repeat marker STM5136 was closely linked to the identified QTL.
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a major qtl and an ssr marker associated with Glycoalkaloid content in potato tubers from solanum tuberosum s sparsipilum located on chromosome i
Theoretical and Applied Genetics, 2008Co-Authors: Kirsten Kørup Sørensen, Hanne Grethe Kirk, Rodrigo Labouriau, K Olsson, Jørgen ChristiansenAbstract:New potato (Solanum tuberosum) varieties are required to contain low levels of the toxic Glycoalkaloids and a potential approach to obtain this is through marker-assisted selection (MAS). Before applying MAS it is necessary to map quantitative trait loci (QTLs) for Glycoalkaloid content in potato tubers and identify markers that link tightly to this trait. In this study, tubers of a dihaploid BC1 population, originating from a cross between 90-HAF-01 (S. tuberosum1) and 90-HAG-15 (S. tuberosum2 × S. sparsipilum), were evaluated for content of α-solanine and α-chaconine (total Glycoalkaloid, TGA) after field trials. In addition, tubers were assayed for TGA content after exposure to light. A detailed analysis of segregation patterns indicated that a major QTL is responsible for the TGA content in tubers of this potato population. One highly significant QTL was mapped to chromosome I of the HAG and the HAF parent. Quantitative trait loci for Glycoalkaloid production in foliage of different Solanum species have previously been mapped to this chromosome. In the present research, QTLs for α-solanine and α-chaconine content were mapped to the same location as for TGA content. Similar results were observed for tubers exposed to light. The simple sequence repeat marker STM5136 was closely linked to the identified QTL.